Oxygen, Lambda Sensor Exhaust Oxygen Sensor (O2 Sensor) Measures oxygen in the exhaust so the ECU can correct the air-fuel mixture MDR "EPS-1997 588" - Not availablePEUGEOT - 206, 207, Partner, 407, 306; CITROËN - C5, Xsara; FIAT - Fiorino, Qubo